The former Manchester United star is of the belief that the teenage striker is making Mourinho's team selection difficult as he provides so much versatility across the front line.
Scholes told BT Sport: "It's going to be very difficult to dislodge someone like that, someone like Zlatan, we know that.
"But I think it's great for him to learn from somebody like that.
"And Marcus has played a lot of his youth team football as a right winger believe it or not but he can play centre-forward and he can play in either wide position.
"I just think he's now at a point where he's making life really difficult for Mourinho to leave him out."